Transparency slide



Dec. 15, 1959 A. PERRQT 2,916,8 0

' TRANSPARENCY SLIDE Filed July 6, 19 55 INVENTOR Arnold Perror BY ATTORNEY w r-r-n United States Patent TRANSPARENCY SLIDE Arnold Ferrot, Nidau, Switzerland Application Jilly 65-1955,- Seria'l N6. 520,259

Claims priority, application- Switzerland September 13, 1954 3 Claims. (Cl. 40-152) The present invention relates to a process for menufacture of a transparency slide, which is characterized in that an inner frame is stamped out in the outer edges of which a V-shaped groove is made, a first metal mask is fixed onto the inner frameby bending the flanges of the mask against one of the walls of the" V-shaped groove, two protective glasses enclosing the transparency are introduced within the inner frame, and then a second metal mask is fixed to the inner frame by bending the; flanges of this second mask against the other wall of the V-shaped groove of the inner frame.

The invention also concerns the slide obtained by the above-mentioned process, as well as an apparatus for carrying out this process. The apparatus referred to ischaracterized in that it comprises a platen supporting on the one hand a stationary stop and on theother hand a movable stop Capable of sliding towards the stationary stop under the action of a lever, both stops being formed by metal plates whose opposite sides have the shape of dihedral an'gles corresponding to the V- shaped groove of the inner frame, the whole being ar-' ranged in such away that by placing the inner frame with one of the masks on'the platen between both stops and by actuating the lever controlling the movable stop, two opposite flanges of the mask are simultaneously bent into the groove of the inner frame, this bending operation having to be repeated for the other pair of flanges of the mask.

The accompanying drawing shows, by way of example, an embodiment of the transparency slide and an embodiment of the apparatus according to the invention.

Fig. 1 is a perspective exploded View of the slide.

Fig. 2 is a perspective view of the slide when assembled and sealed. I V t M Fig. 3 is a cross-sectional view of the slide shown in Fig. 2.

Fig. 4 is a perspective view of the apparatus.

Fig. 5 is an inverted-plan view at an enlarged scale of a detail of the apparatus of Fig. 4, some parts being broken away.

Fig. 6 is a cross-sectional view, at the same scale as Fig. 5, of the apparatus of Fig. 4.

For manufacturing the transparency slide shown in Figs. 1 to 3 an inner frame 1 of rectangular or square shape is first stamped out. This frame 1 may be made of any suitable material, preferably of a plastic material such as Plexiglas or the like. A groove 2 having a V-shaped section is made in the outer edges of the frame 1. A first mask 3 whose thickness is very small with respect to that of the frame 1 is then secured to the inner frame 1. The mask 3 is formed of a metal plate having a rectangular opening 4. This opening has smaller dimensions than the opening 5 of the frame 1, for the reason indicated below. The mask 3 has on its periphery vertical flanges 6. The metal used for the mask 3 is preferably aluminium. For securing the mask 3 onto the inner frame 1, the flanges 6 are bent against one of the walls of the V-shaped groove 2. This bend- 2 ing operation may advantageously be made by means of the apparatus shown in Figs. 4 to 6. Fig. 3 shows the bent position of the flanges 6.

Two protective glasses 7 and 8 maintaining between them the transparency or diapositive 9 are then put in place witln'n the inner frame 1. The thickness of the several parts of the slide is such that both glasses 7, 8 and the transparency 9 have together the same thickness as the inner frame 1 (see Fig. 3). As the opening 4 is smaller than the opening 5 of the frame 1, a bearing surface 10 is provided on the mask 3 (Fig. 3), thus maintaining the glass 7 in its axial position. v

A second mask 11 similar to the mask 3 has still to be secured to the frame 1. The flanges of the mask 11 are denoted by the numeral 12. The fixation of the maskjl l is made in the same manner as that of the first mask 3, the flanges 12 hearing in their bent position against the second wall of the V-shaped groove 2.

Owing to the inner frame 1, it is practically impossible for dust to penetrate within the slide and to impair the transparency 9.

When the slides are brought onto the market and sold, the first mask 3' is already secured to the inner frariie 1, so that for assembling and sealing the slide, it is sufficient to insert the glasses 7 and 8 with the transparency 9 into the frame 1 and to fix the second mask 11, the whole operation being quickly performed. If the transparency 9 of an already sealed slide is to be replaced, it suflices to tear out the mask 11 by raising its flanges 12 and to fix a new rnask onto the frame 1. For this purpose spare masks are preferably sold with the complete slides.

The apparatus shown in Figs; 4 to 6 considerably facilitates the sealing of the slides described above. This apparatus comprises a platen 13 having a U-shaped section and supporting on the one hand a stationary stop 14 and on the other hand a movable stop 15 capable of sliding towards the stationary stop 14 under the action of a lever 16. Both stops 14 and 15 are formed by metal plates whose opposite sides have the shape of dihedral angles 17 corresponding to the V-shaped groove 2 of the inner frame 1 of the slides.' The stationary stop 14 has two lateral horns 18 (Fig. 4) serving for centering the slide when it is being sealed. A small plate 19 fixed to the stop 14 has an extension 20 which is slightly bent upwards. The parts 14 and 19 are fixed to the platen 13 by any suitable means, for instance by spot-welding. g

The movable stop 15 is traversed by two screws 21 engaging grooves 22 of the platen 13. The heads 23 of the screws 21 cause the movable stop 15 to bear against the upper face of the platen 13.

The lever 16 is pivoted on a shaft 24 journalled in the walls 34 of the platen 13. It is subjected to the action of a coil-spring 25 which tends to swing it in the clockwise direction of Fig. 6. The lever 16 has two lugs 26 in which is journalled a shaft 27. On the latter is pivoted a connecting bar 28 the free edge of which comes within reach of the movable stop 15. The stop 15 presents a T-shaped projection 29, and a cut-out part 30 of corresponding shape is provided in the bar 28, so that the members 15 and 28 are interlocked (Fig. 5). A small plate 31 is fixed to the movable stop 15 by means of the screws 21. It has on the one hand a portion 32 slightly bent upwards and on the other hand a portion 33 bearing against the connecting bar 28 when the lever 16 has the position shown in Fig. 6.

Let us assume that the second mask 11 has to be secured to the inner frame 1. The slide is placed between both stops 14 and 15 on the platen 13 of the apparatus (Fig. 4) in such a manner that the mask 11 lies on the side of the platen 13. The lever 16 is then lowered, so

Patented Dec". 15, 1959' that the connecting bar '28 pushes the movable stop 15 towards the left of Fig. 6. The dihedral angles 17 of the stops 14 and 15 simultaneously press two opposite edges of the slide and bend the flanges 12 of the mask 11 into the V-shaped groove 2 of the inner frame 1. The

the apparatus and prevent the slide from being lifted dlll",

ing the sealing operation.

The bending operation of the flanges of the mask is then repeated for the other pair of opposite flanges.

The flanges of the masks are not bent up to their ends, i.e. they remain upright at the corners of the slide, as clearly shown in Fig. 2. Therefore, a substantial reinforcement of the slide is obtained and these corners remain clean, as no accumulated material projects beyond the dimensions of the slide.

The disclosed slide for transparencies has a vary low cost and its sealing by means of the apparatus described is easily performed.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What I claim is:

1. A slide mounting comprising an inner frame made of plastic material, the frame having an opening therein, the outer edges of the frame having a V-shaped groove at least in the center portions of the edges thereof, a pair of protective glass plates accommodated in the opening of the inner frame and adapted to receive a transparency therebetween, and a pair of identical windowed thin metal masks, flanges extending transversely of the plane of the masks at one side thereof on all edges thereof, the length of the flanges being approximately one half of the thickness of the mounting and being such that when in position against the inner frame with the edges of the flanges of opposite masks in abutting relationship at least at the corners of the mounting the faces of the masks hold the glass plates in close engagement with the transparency positioned therebetween, the edges of the flanges being bent inwardly into the V-shaped groove along at least a portion of the length thereof and intermediate the ends thereof thereby providing a unitary assembly, the thickness of the parts being equal on both sides of the transparency so that the surfaces of the slide mounting are the same distance from the center line plane of the transparency.

2. A slide mounting comprising an inner frame, the frame having an opening therein, the outer edges of the frame having a V-shaped groove at least in the center portions of the edges thereof, a pair of protective glass plates accommodated in the opening of the inner frame and adapted to receive a transparency therebetween, and a pair of identical windowedthin masks, flanges extending transversely of the plane of the masks at one side thereof on all edges thereof, the length of the flanges being approximately one half of the thickness of the mounting and being such that when in position against the inner frame with the edges of the flanges of opposite masks in abutting relationship at least at the corners of the mount- 1 ing the faces of the masks hold the glass plates in close enof plastic material, the frame having an opening therein, a

pair of protective glass plates accommodated in the opening of the inner frame and adapted to receive a transparency therebetween, and a pair of identical windowed thin metal masks, flanges extending transversely of the plane of the masks at one side thereof on all edges thereof, the length of the flanges being approximately one half of the thickness of the mounting and being such that when in position against the inner frame with the edges of the flanges of opposite masks in abutting relationship at least at the corners of the mounting the faces of the masks hold the glass plates in close engagement with the transparency positioned therebetween, the thickness of the parts being equal on both sides of the transparency so that the surfaces of the slide mounting are the same distance from the center line plane of the transparency.

References Cited in the file of this patent UNITED STATES PATENTS 754,941 Ross Mar. 15, 1904 1,374,324 Reznor Apr. 12, 1921 1,440,561 Singewald Jan. 2, 1923 1,797,418 Hothersall Mar. 24, 1931 1,969,120 Coakley Aug. 7, 1934 2,127,982 Northrop Aug. 23, 1938 2,168,631 Scott Aug. 8, 1939 2,176,283 Whiteford Oct. 17, 1939 FOREIGN PATENTS 677,494 Germany June 27, 1939 272,287 Switzerland Mar. 1, 1951 

